分享一个自用的Http客户端

准备工作

  
    org.apache.httpcomponents
    httpclient
    4.5.13
  
  
    commons-fileupload
    commons-fileupload
    1.3.3
  

创建HttpUtils.java

public class HttpUtils {
    private final static Logger logger = LoggerFactory.getLogger("-----HttpUtils-----");
    private final static int RESULT_OK = 200;
    private Map headers;
    private CloseableHttpClient client;

    private HttpUtils() {
    }

    public static HttpUtils create() {
        return new HttpUtils();
    }

    public HttpUtils client(CloseableHttpClient client) {
        this.client = client;
        return this;
    }

    public HttpUtils headers(Map headers) {
        this.headers = headers;
        return this;
    }

    public String get(String url) {
        try {
            return getResult(url);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String getDownLoad(String url, String dir, String name) {
        try {
            return downLoadFile(url, dir, name);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String post(String url, Map param) {
        HttpEntity entity = new UrlEncodedFormEntity(createParam(param), Consts.UTF_8);
        try {
            return postResult(url, entity);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String post(String url, String param) {
        HttpEntity entity = new StringEntity(param, Consts.UTF_8);
        try {
            return postResult(url, entity);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String postDownLoad(String url, String param, String dir, String name) {
        HttpEntity entity = new StringEntity(param, Consts.UTF_8);
        try {
            return downLoadFile(url, entity, dir, name);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public RequestConfig config() {
        // 配置信息
        return RequestConfig.custom()
                // 设置连接超时时间(单位毫秒)
                .setConnectTimeout(5000)
                // 设置请求超时时间(单位毫秒)
                .setConnectionRequestTimeout(5000)
                // socket读写超时时间(单位毫秒)
                .setSocketTimeout(5000)
                // 设置是否允许重定向(默认为true)
                .setRedirectsEnabled(true).build();

    }

    private String postResult(String url, HttpEntity entity) throws Exception {
        HttpPost post = new HttpPost(url);
        if (null != headers && !headers.isEmpty()) {
            headers.forEach(post::addHeader);
        }
        CloseableHttpClient httpClient = null != client ? client : HttpClientBuilder.create().build();
        post.setConfig(config());
        post.setEntity(entity);
        return getResultString(httpClient.execute(post));
    }

    private String getResult(String url) throws Exception {
        CloseableHttpClient httpClient = null != client ? client : HttpClientBuilder.create().build();
        HttpGet get = new HttpGet(url);
        if (null != headers && !headers.isEmpty()) {
            headers.forEach(get::addHeader);
        }
        get.setConfig(config());
        return getResultString(httpClient.execute(get));

    }

    private String downLoadFile(String url, HttpEntity entity, String dir, String name) throws Exception {
        CloseableHttpClient httpClient = null != client ? client : HttpClientBuilder.create().build();
        HttpPost post = new HttpPost(url);
        if (null != headers && !headers.isEmpty()) {
            headers.forEach(post::addHeader);
        }
        post.setConfig(config());
        post.setEntity(entity);
        return download(httpClient.execute(post), dir, name);

    }

    private String downLoadFile(String url, String dir, String name) throws Exception {
        CloseableHttpClient httpClient = null != client ? client : HttpClientBuilder.create().build();
        HttpGet get = new HttpGet(url);
        if (null != headers && !headers.isEmpty()) {
            headers.forEach(get::addHeader);
        }
        get.setConfig(config());
        return download(httpClient.execute(get), dir, name);

    }

    private String getResultString(CloseableHttpResponse execute) throws IOException {
        try (CloseableHttpResponse response = execute) {
            HttpEntity httpEntity = response.getEntity();
            int code = response.getStatusLine().getStatusCode();
            String result = EntityUtils.toString(httpEntity, StandardCharsets.UTF_8);
            logger.debug(result);
            if (RESULT_OK == code) {
                return result;
            } else {
                return null;
            }
        }
    }

    private String download(CloseableHttpResponse execute, String dir, String name) throws IOException {
        try (CloseableHttpResponse response = execute) {
            HttpEntity httpEntity = response.getEntity();
            File dirs = new File(dir);
            if (!dirs.exists()) {
                dirs.mkdirs();
            }
            File file = new File(dirs.getAbsolutePath(), name);
            FileUtils.copyInputStreamToFile(httpEntity.getContent(), file);
            return dirs.getAbsolutePath() + "/" + name;
        }
    }

    private static List createParam(Map param) {
        //建立一个NameValuePair数组，用于存储欲传送的参数
        List nvps = new ArrayList();
        if (param != null) {
            for (String k : param.keySet()) {
                logger.debug(k + ":" + param.get(k).toString());
                nvps.add(new BasicNameValuePair(k, param.get(k).toString()));
            }
        }
        return nvps;
    }

    public static void main(String[] args) {
        String url = WxUtils.ACCESS_TOKEN;
        url = url.replace("APPID", "xxxxxxxxxxxxxxx");
        url = url.replace("APPSECRET", "xxxxxxxxxx");
        String ret = HttpUtils.create().get(url);
        System.out.println(ret);
    }
}

调用结果

获取微信AccessToken
{"access_token":"xx_xXXXXXXXXX-XXXXXXXXXXXXXXXXXXXXX_XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX","expires_in":7200}